The present invention relates generally to locking pivot mechanisms and, more particularly, to a seatback latch mechanism operable for locking a seatback in an upright position and a folded position.
Seat assemblies of the type used in motor vehicles are commonly equipped with locking pivot mechanisms which can be selectively actuated to permit angular adjustment of the seatback relative to the seat bottom, thereby providing added comfort and convenience for the seat occupant. Typically, these locking pivot mechanisms include a housing fixed to the seat bottom, a quadrant fixed to the seatback and which is supported from the housing for pivotal movement about a first pivot point, a lock pawl supported from the housing for pivotal movement about a second pivot point, and a release actuator for causing movement of the lock pawl between first and second positions. In its first position, teeth on the lock pawl engage teeth on the quadrant for preventing movement of the quadrant about the first pivot point, thereby releasably locking the seatback in a desired position. In contrast, movement of the lock pawl to its second position causes its teeth to disengage the teeth on the quadrant and permit angular movement of the seatback to a desired position. Typically, the release actuator includes a spring-biased cam for normally locating the locking pawl in its first position. In many seating applications, this type of locking pivot mechanism is used as a seat recliner to permit selective adjustment of the seatback between an upright position and a fully-reclined position.
Recently, however, with the increased popularity of pickup trucks, minivans, and sport-utility vehicles, there has been an interest in developing seat assemblies in which the seatback is capable of folding forward to a dumped position for providing improved accessibility to storage space or providing increased cargo area. In pickup trucks, the ability to fold the front seatbacks completely forward permits access to the rearward cab compartment. In mini-vans and sport-utility vehicles,the ability to fold the rear seatbacks completely forward enables the cargo space to be increased or ingress to be simplified. In known designs, the seat assembly is equipped with a seatback dump mechanisms which typically employs some variation of a pawl-type locking pivot mechanism. Although pawl type pivot mechanisms enable a seatback to be reclined to a substantially flat position, they may not enable the seatback to be folded completely forward to improve accessibility to storage space or provide increased cargo area. Furthermore, it should be appreciated that vehicular seats must be capable of withstanding extreme forward and rearward forces which result from belt loading caused during a collision incident. In pawl-type pivot mechanisms, these forces are transmitted to the pawl and the quadrant. As such, the cam must be designed to withstand these extreme forces, which increases the complexity and cost of the seatback dump mechanism.
Accordingly, a need exists in the relevant art to provide a seatback dump mechanism for latching the seatback in an upright position and a folded position so as to enable improved ingress and versatility of the vehicle. Furthermore, a need exists in the relevant art to provide a seatback dump mechanism capable of providing the folding function while maximizing structural integrity of the seatback dump mechanism and simultaneously minimizing the overall cost of the system.